Radiant Fire Not Drawing

Morning!

Sorry if this is in the incorrect forum.

I have a Flavel Regent radiant fire, connected to an original 50's unlined brick chimney (so, I guess, a class I flue). The chimney pot (I believe a "Louvre" anti-downdraught pot) is pictured below.

The CORGI guy came yesterday to do a safety check, and disconnected the fire as he says it wasn't drawing properely (smoke matches leaked into room through the vent on top). He thinks it might be the pot but didn't seem sure.

Can anyone confirm if the pot could stop the fire drawing? Is it worth getting a second opinion? I phoned a chimney pot shop who disagreed and said that the pot was suitable. I swept the chimney myself a couple of weeks ago and saw the brushes coming out of the pot myself.

Thanks very much!

Those louvred pots are "intended " to help downdraught ...........get the gas fire removed and enjoy a coal/log fire...forget the gas fire unless you want to play with the grim reaper

Hmm, interesting!

I had another gas fire guy round today, who said that the chimney was fine, and that the pot was designed to increase UPdraught, so was absolutely fine for a gas fire.

He reckons the problem could be with the fire, suggested it might be the heat exchanger. Does anyone have any experience with these fires? Might a service cure the problem?

Thanks

Try a spillage test with a window slightly open. You could need additional ventilation

I checked the manual first as I thought there might be a flue restrictor either missing or needed.
Couldnt see anything about one there but I only had a quick glimpse of it so check for yourself

cb9002 said:

Hmm, interesting!

I had another gas fire guy round today, who said that the chimney was fine, and that the pot was designed to increase UPdraught,

Thanks

Click to expand...

No it`s not .....it`s as I said a Marcone or H pot has a chance of increasing UP draught........that one is intended to dissipate downdraught thru` the louvres .......19th. Century idea for coal fires

Had a quick look in a book -. That type it says is "not considered acceptable for most gas burning appliances".
I can't see it making a lot of difference to the draw of a flue, with quiet winds, so wouldn't pin my hopes there.
Did the tester give the chimney 10/20 minutes to warm up?

Thanks all...

There's no flue restrictor, but there is a metal plate between the fire and the chimney, through which the fire exhaust protrudes.

The spillage test was fine with the patio door open. Unfortunately this room only has a patio door and no other ventilation. The test was also done with the internal doors open and the patio door shut, when leakage didn't occur, which the CORGI guy took as meaning ventilation was ok.

The fire was run for about 3-4 mins before the spillage test was carried out, the plate under the fire says 5 minutes on full is sufficient. Would you suggest a bit longer in case?

Nige F, I hope you didn't take it the wrong way - just repeating what the gas men tell me! Could you explain why anyone would want a pot that would cause downdraught?

ChrisR, the second guy held a lighter in front of the backplate and showed an updraught, as the lighter flame was drawn into the fire. Might be a different matter with the fire running?

Slugbaby.com thanks for the link!

From the installation instructions...

3.3 Checking for Clearance of Combustion Products
a) Close all doors and windows in the room. Remove the dress guard.
b) Light the fire and turn to the maximum position.
After 5 minutes hold the smoke match as shown in Fig. 4. Whilst hold
ing the smoke match in the correct position, approximately 5mm below
and inside the lower edge of the centre of the canopy.
Ensure that most of the smoke is drawn into the flue aperture. If in
doubt repeat the exercise after a further 5/10 minutes.
Note:- It is recommended that the smoke match is fitted into an approved
smoke match holder, when checking for clearance of combustion
products.

OK, so what is "most", how much leakage is permissable? And, when it says "into the flue aperture", does that mean into the chimney? The smoke was drawn above the radiants, but came out of the gold louvered vent at the top.

Sorry for all the detail!

Is the closure plate correctly sealed all around the edges but leaving the relief holes uncovered.

Use a smoke match holder - thats a tube with the match inserted in the end otherwise the smoke will be ejected from the match at all angles.

The manual also says to remove the flue spigot restrictor (it comes factory fitted) if it fails the spilage check and try again.

The smoke should be drawn into the flue.

Flavel regent usually has a piece of glass at top front of radiants which is the width of radiants by about 2 inches deep does yours have this a lot have been broke over the years and stop fire pulling properly

Hi Gasguru

The closure plate has been sealed around the edges with fire cement, and the three holes at the bottom are open. Please could you explain to me what the flue spigot restrictor is - should I take the casing off and remove some sort of a plate from the "Exhaust"?

Namsag, the glass is in good condition but thanks for the suggestion.

The flue spigot is the gas fires equivalent of an exhaust pipe.
A restrictor reduces the the size of the flue spigot.

I still didn't see a reference to a restrictor after another look at the instructions.
So hopefully if you remove the flue spigot from the back of the fire by removing the 4 screws, then the restrictor plate, if indeed there is one, should come off Then you can re-attach the flue spigot.

cb9002 said:

The closure plate has been sealed around the edges with fire cement, and the three holes at the bottom are open. Please could you explain to me what the flue spigot restrictor is - should I take the casing off and remove some sort of a plate from the "Exhaust"?

Click to expand...

According to the manual the closure plate only has TWO relief holes at the bottom - are you sure it is the correct plate (often the fire model is written on it) or has the installer cut a new hole? The plate should be sealed at ALL edges with closure tape (PRS10) not fire cement. Fire cement is brittle, will crack and allows air to enter the fireplace opening at the edges affecting fire safety. Before the tape is applied the wall surface must be prepared correctly to allow the tape to adhere.


From the manual:

1.6 CLOSURE PLATE
A closure plate is supplied with this fire and must be fitted. The closure plate must
be sealed to the fireplace or surround opening with suitable adhesive tape. See
section 2.2.2

And from section 3.3e

e) If the smoke is not drawn into the flue aperture, remove the flue spigot
restrictor if fitted and repeat the spillage test.

It appears your installer doesn't know what he's doing - I sugest you find someone else. I dis-connect 90% of gas fire I come across - many are poorly installed. Get yourself a carbon monoxide alarm - from recent events the effectiveness of the safety devices fitted to fires may have been exaggerated somewhat.

last comment says it all........No offence taken -or intended,,,but some highly qualified people guess@ what they Think a simple looking thing is for......like your CORGI might not have known what a louvred pot is trying to do ...to a coal fire chimney Me, I couldn`t be a gasman ........no sense of smell

Gas fires are a pretty dodgy commodity in my view. I hate them, and the older they get the more I hate them. I fall firmly into the "If in doubt, rip it out" camp.

First. The closure plate has to come off and the builders opening checked and cleared.
Second. It has to be resealed with closure tape (we use foil)
Third. Do a flue flow smoke bomb test with a cold flue. All doors and windows shut. If it works cold, then you are pretty well guaranteed its ok when hot. If it doesn't work you can warm it up a bit with your gas gun (never quite convinced about this) and try again. Either way you need to know the flue performs robustly.

Refit fire, examining flue spigot for restrictor plate beforehand, and remove radiants and check the metal heat exchanger behind for corrosion/cracks. If you have smoke coming out of the top louvres this is a possibility, and I see it now and again.

Then do the spillage tests as previously directed. If my first two tests are not convincing after a short heat up time, I give it a clear ten minutes running at full to get the appliance and the flue nice and hot. If it doesn't give a pretty clear pass after that....its in the skip.

I find that short flues in bungalows are pretty marginal at times of high atmospheric pressure when testing in hot weather. I rarely see problems in two storey house flue performance though.

As to THAT chimney pot..my take is that in updraft conditions it will assist the flue adding to the pull. In downdraft conditions it will divert SOME of the downdraft away from the flue..and reduce its effect on the flue. Too simple..or what?

Alfredo